It is known, for instance, from US 2004/0102686 to carry out methods of diagnosis for identifying vulnerable plaque by identifying pathological markers such as C-reactive protein or pH change generated by the pathological site. US 2004/0102686 describes an arrangement where first and second detectors are advanced through a blood vessel with each of the detectors selected to detect the pathological marker. The detectors are spaced axially apart such that differential concentration of the pathological marker as measured by the detectors indicates the presence of the pathological site in proximity to at least one of the detectors. The use of detectors in this way is somewhat limiting and relatively expensive. Specific detectors have to be provided for respective tests, fitting these detectors in the catheter is relatively difficult and, where a variety of different catheters are provided, each requires separate regulatory approval. Furthermore, the spacing of the detectors is such that any markers for detection have been diluted throughout the blood volume such that their concentration is significantly affected by the general background level and it becomes more difficult accurately to identify the source of the markers.
U.S. Pat. No. 5,533,516 describes taking a bodily sample, e.g., a cell sample, from deep within the body of a patient and collecting the sample outside the body to facilitate treatment of the patient. A sampling probe is provided in the form of an elongate catheter having a proximal portion that remains outside the body and a distal portion that can be located within the body. The distal portion includes a membrane with openings that communicate with space that communicates with a source of suction force. The catheter is positioned within the body. The sample is taken by exposing the membrane by placing it in proximity with a desired location so that the bodily sample is received by the membrane. The catheter is removed from the patient, the sample is collected outside the body, treated, disposed onto a device, such as a graft, stent, or catheter, and reintroduced into the body at a desired site.
GB 1 405 556 describes an endometrial sampler, comprising a hollow tube having a sampling end containing a plurality of sampling ports communicating with the interior of the tube, and a sleeve surrounding the tube and slidable with respect to it, the sleeve and the tube being reciprocable with respect to one another between a sampling position in which the sleeve exposes at least one of the sampling ports and a second position in which the sleeve engages a forward stop on the tube and covers all the sampling ports.